DNS Records

A guide to the different types of DNS records and how to use them effectively.

A Records

A (Address) records map a domain name to an IPv4 address. This is the most common record type for pointing a domain to a web server.

example.com.  A  198.51.100.1

AAAA Records

AAAA records are like A records but for IPv6 addresses. If your server supports IPv6, you should create both A and AAAA records.

example.com.  AAAA  2001:db8::1

CNAME Records

CNAME (Canonical Name) records alias one domain name to another. They're commonly used to point www.example.com to example.com.

www.example.com.  CNAME  example.com.

Note: CNAME records cannot coexist with other record types at the same name.

MX Records

MX (Mail Exchange) records specify mail servers for a domain. Each MX record has a priority value - lower values are preferred.

example.com.  MX  10  mail.example.com.
example.com.  MX  20  backup-mail.example.com.

TXT Records

TXT records hold text information. They're commonly used for:

  • SPF records (email authentication)
  • DKIM keys (email signing)
  • Domain verification tokens
  • DMARC policies
example.com.  TXT  "v=spf1 include:_spf.google.com ~all"

TTL (Time to Live)

TTL tells DNS resolvers how long to cache a record. Lower TTLs (60–300 seconds) are useful when testing changes. Higher TTLs (3600–86400 seconds) reduce DNS query load.

Best Practices

  • Set low TTLs (60s) before making major changes
  • Always verify records with dig or nslookup
  • Keep at least two nameservers for redundancy
  • Use CNAME records for subdomain delegation when possible